it wasn't a full on ban, but I do remember drama a year or two ago when Tumblr banned LGBTQ+ content from their safe search. This was also eventually backtracked.
I have a feeling that it's possible we're going to see this ban play out the same way, I'm not sure.
As many people have pointed out here and elsewhere -the platform is largely used for porn, and once those users are driven out you'll just be left with tumblweeds.
I feel like there's a 50 percent chance that is going to occur to someone up the food chain in the next couple of weeks, and this policy will be quietly walked back.